Questions tagged [hvac]
(Heating, Ventilating, and Air Conditioning) For questions about installing, repairing, and troubleshooting HVAC systems.
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Bathroom Fan switch ground vs Neutral
I'm sure this has come up before. I have been reading a lot about improper Neutrals or rather using ground as Neutral.
From what I can tell, the Neutral and Ground touch in the panel. I thought the ...
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What is this thin steel wire connected to the ungrounded side of a two-wire cable in my basement ceiling?
I recently purchased a home (built in the 50s, northern USA) and the man who previously lived there definitely did some DIY work around the house. I found a mess of (seemingly disconnected) wiring ...
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Hardware issues with 2 series condensers with heat pump in heat mode [migrated]
I am planning to use a second heat exchanger to added inline to remove heat from a standard mini split heat pump system. The refrigerant will flow from the compressor to an added water coil exchanger, ...
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Find replacement HVAC transformer
I want to replace this HVAC transformer but I don't know any of the specifications or ratings for the existing one. This is hooked up to the heater in my garage/shop and the heater fails to kick on ...
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In practice, is it problematic to vent a gas-fired boiler under a bay window?
I am having a 199 kBTU direct vented gas-fired combination boiler installed. Because of how the house is arranged, it's difficult to find a good place to vent the exhaust. The easiest spot is ...
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Connect an in-line fan to the thermostat
I’m trying to connect an inline booster fan to my ecobee3. The fan I have is an AC INFINITY CLOUDLINE T6. I would like to have it turn on whenever the fan of the HVAC is turned on.
The in-line fan has ...
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How to waterproof foam and pipes coming up through concrete ground
I have a bundle of foam and pipes coming up through the concrete ground in my backyard for my HVAC equipment. There is no conduit and the pipes and foam is all in ground contact and the concrete was ...
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Which breaker controls the HVAC unit?
I want to inspect the thermostat wiring in my apartment. It's an old White Rodgers so I have to turn off the breaker before removing the thermostat housing.
My apartment has an HVAC unit that looks ...
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Gas furnace takes like 2-5 minutes from ignition to blower start. flame also burning yellow/orange
It's still heating the house which is why we have never considered it a problem so far this season. However I recently got a smart thermostat and really started noticing how long the startup takes to ...
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Zone 2 smart thermostat c wire voltage question
I upgraded my zone 1 and zone 2 t stats to smart units. Zone 1 works fine, I have 24-28v testing red to c wire at zone 2 when zone 1 is turned on, if zone 1 is not running, I have nothing at zone 2.
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blower moter on my hvac dosent work after changing both capacitors [closed]
my blower motor on my havoc stopped working so I changed both of the capacitors. when I set the inside thermostat to just fan the blower motor works but very slowly and does not work at all when I set ...
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AC Condensor Motor Wiring
I am replacing the AC condenser motor , the original had 3 wires, black, purple and brown, in the dual capacitor the brown is to the fan and purple to the common.
My replacement motor has 2 black and ...
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Can I use rigid metal 90s with flex duct?
I am trying to correct poorly installed ductwork. Everything is duct-board and flex duct. None of the flex duct is pulled tight and the 90s are pulled around truss webs so those have kinks inside the ...
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Why does hooking voltmeter to two transformers show 0 voltage?
I have two 24VAC transformers. If I hook the voltmeter to contacts 1 & 2, or 3 & 4, it measures about 26 volts. If I connect it to 1&3 or 1&4, or 2&3 or 2&4, I get zero. I ...
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Why would a plug-in radiator appear to be much more effective than a PTAC unit?
There is a room in an apartment that is heated by a packaged terminal (PTAC) unit. Based on the smart meter, during the night if the temperature is set to around 73 degrees Fahrenheit the PTAC unit ...
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Should an inverter heat pump be sized according to the conventional AC unit it replaces?
A split conventional AC needs to be replaced due to age. The current AC is 48K BTU (4-ton).
If replaced with an inverter heat pump, should it be sized with a 48K BTU unit? Or should it be sized with ...
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What would cause a furnace to randomly fail to light roughly once a week?
Roughly once a week my furnace will shut off. No error codes are flashing. I turn the switch off and turn it back on and it will relight without an issue or error. There was a single occasion where it ...
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Heat pump for additional heating capacity in downstairs of house
My house (Portland, OR, 2900 sq ft) has central gas heating and central AC. The house was built in 2017 and is well insulated, but every winter we face an annoying problem: downstairs and upstairs ...
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How is a "Split" Air Conditioner Heat Pump System different from a garden variety Heat Pump? [closed]
I would like to replace my 4-ton HVAC (for a my storage facility, requiring only cooling), which is similar to this Goodman device. Assume the site is in North Florida (Jacksonville). There is no ...
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How can I identify my electric furnace?
I have a woodchuck wood and coal furnace which someone added an electric heater on top of. The issue is I can't identify the electric heater, and it's in need of some servicing. Anyone recognize ...
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What is the equation used with duct sizing charts?
What is the equation used with duct sizing charts?
I can look at duct sizing charts and they're all the same so if I point to as an example:
https://hvacdirect.com/hvac/pdf/Field_duct-sizing-chart.pdf ...
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Sizing an emergency generator for an old AC with a missing label
My daughter is trying to work out the current draw of an old AC with a worn label. She's trying to size an emergency generator that will power critical appliances in the event of a power outage. The ...
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Should I cut out this repaired kink in a copper line set? (3/8")
I'm installing a mini-split, and in a moment of carelessness I slightly kinked the 3/8" copper line (the larger one). I repaired it using the 'wrench method' with some nylog to lubricate, and now ...
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Furnace return sucking in drafts throughout home
Why would it be that when the furnace blower is running, cold air is being sucked into the house from every nook and cranny, in all rooms? 832 sq ft old home with downflow furnace on main level ...
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Lenox Furnace won't stay lit [closed]
The code I have been getting is the alternating slow flash - watchguard. burners failed to ignite or lost flame 5 times during heating cycle. I have already cleaned the flame sensor but it still fails ...
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Reduce light and sound from adjacent rooms sharing air return vents
My two bedrooms upstairs share a wall space for an air return. The wall has an upper and lower return vent. You are able to see directly into the adjacent room from the vents. Is there anything that ...
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Required Circuits for Waterfurnace Geothermal Unit and Aux Heater
I am pulling the permit and installing the electrical wiring for my Waterfurnace 7 Series 4-ton Ground Source Heat Pump / Furnace. These are the components:
7 SERIES 700A11 Model 048 (Reference ...
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Reduced ducted air flow with heat pump
This post is part of the research I did before installing a heat pump recently, which may help add context: Gas furnace switch to heat pump installation?
The heat pump I got installed is ...
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Outside unit won’t work when inside blower fan spins correct way only when it is going wrong direction
I have a universal motor on my inside electrical unit. It runs but doesn’t have much air flow (like can barely feel anything even from the closest vent) so I swapped the direction wires and it gave me ...
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Need help wiring Alexa smart thermostat
I have an 2002 unit Condo. I have installed Alexa smart thermostat. I replicated the exact wiring but thermostat only blowing hot air even when it says cooling is running.
Orange wire went to 'W' and ...
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How do I go about wiring 3 Nests to a boiler with no C wire
I’ve seen a version of this question in a few places but nothing really fits.
I have a boiler and hot water baseboards. It’s a three zone system and I installed 3 Nests but there is not C wire and no ...
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Do I need to add a return in one of my bedrooms
My house was built in the 70s and the master bedroom has 2 supplies but no return. The other two bedrooms, which are smaller, each have 1 supply and 1 return.
The bathroom right next to the master ...
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Problem changing to a new timer with self-installed ground wire in old NYC building
I am trying to change my Lutron timer to a new timer (which needs to be grounded). My home is a NYC condo built in 1950s - so I guess I have AC cables. I did not see any ground wire inside the metal ...
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Best way to move this dryer vent hookup?
I am adding a sink to my laundry room on the right hand side of my dryer. The washing machine and related plumbing is on the left hand side of the dryer, so in order to tap off the drain for the new ...
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Thermostat common wire identification for Nest thermostat
There are 5 wires at the old thermostat. No C wire. Dual system. At HVAC unit there is no mother board, only wire caps. The colors don’t match between thermostat and outside unit. I'm trying to ...
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Hydronic floor floor system problem
Here's a picture of my hydronic floor heating system with three zones.
A tech came out and told me that the feeder was bad. He also told me that on the controller board everything's working as it ...
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Ecobee Learning Enhanced—3 zones-2 slave thermostats
I have a 3 zone HVAC system. I have one “master” thermostat that can switch the entire system off and on as well as switch back an forth between heating and cooling. The other 2 thermostats are “...
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Heat Pump only heating for a few mins
I have a heatpump that will only run for a few mins before shutting off, inside blower runs nonstop. Cycles on again in about 45-60mins.(vent blows out warm air the first few mins then room temp air ...
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Inducer motor is not spinning
My furnace is not working. I see that the inducer motor (Fasco 70623925) is not spinning (it turns freely when I spin it by hand though). The motor threatens to run when the heat signal is received, ...
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How should I modify piping for a Burnham Series 2E when the Indirect Water Heater is not used?
Can you provide a sketch (and if possible, a photo of a similar layout) of the piping if I omit the Indirect Water Heater as shown in the attached image taken from page 11 of the Burnham Series 2 ...
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Is a Cold Climate Heat Pump The Best Option to Replace Gas Furnace? [closed]
I live in the Canadian prairies (cold winter -30C or below possible, hot summer +30C or above possible). I recently purchased an AC unit and have had it installed. Recently, my circuit board on my gas ...
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Luxair F2FP048N06H, 2 stage heating and single stage cooling. No PC Board
My Luxair F2FP048N06H, PC board was removed a while back, and I do not have a schematic for the way it was hard wired. Does anyone have a wiring diagram so I can wire the unit back without a circuit a ...
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Duct to vent connection too close and awkward
I recently finished adding an office to the house. There is ductwork running along the unfinished wall of the new room, and I picked out a good place on the wall to add the vent.
What I didn't ...
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I'm trying to connect a thermostat C-wire... no voltage between W/R and COM on control board?
I am trying to add a C-wire for a smart thermostat on an existing gas furnace heater (no cooling). The control board is a HK42FZ065 and the condensate pump a cb151ul.
I tried measuring the voltage ...
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How To Optimize This Bathroom Fan Duct?
I recently installed a new bathroom exhaust fan, replacing a loud and underpowered one with a quieter and more powerful (110cfm) fan. Because of the existing framing and roof vent location, I was ...
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Can the exhaust of a range hood be insulated between the 6in duct and the chimney casing?
I am installing a range hood and I would like to reduce suction and vibration noise as much as possible.
Is it possible to insulate the empty compartment between the 6in exhaust duct pipe and the ...
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Ecobee Thermostat / Common Maker / Gas Valve
I have a two-wire thermostat and an old forced air gas furnace in my house. When you open up the cabinet, inside you find a Dayton 2E228 Gas Valve and it is wired to an external 24VAC Transformer ...
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HVAC return duct near ceiling next to supply duct?
I've owned this home for about a year and this has always intrigued me. My 2-story home has a supply duct nearly pointing at a return duct in the center of the hall upstairs.
Two questions:
Would hot ...
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I'm trying to control heat remotely in a shop/garage that is subject to sub-freezing temps (which is OK with me when it is not in use)
I've learned that smart thermostats go into LO mode when temps drop below 35 and refuse to call for heat when in that mode. I've replaced the smart thermostat with a cheap mechanical thermostat that ...
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How common is it for AC evaporation coils to develop leaks after three months?
Bought new Goodman HVAC unit in September 2022. Evaporator coil has a leak after three months and needs to be replaced. How common is it for that to happen?
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